Image system troubleshooting:
Half self-test functional check
The electrophotographic process can be subdivided into the following stages:
Cleaning (removes excess toner from drum surface)
Conditioning (places a uniform electrical charge on drum)
Writing (laser strikes surface of drum and creates latent image)
Developing (forms the toner image on drum)
Transferring (charge transfers the image to print media)
Fusing (heat and pressure produces a permanent image)
The purpose of the half self-test check is to determine which stage is malfunctioning. Perform the
test as follows:
1 Print a configuration page from the control panel information menu.
2 Open the top cover after the paper advances halfway through the printer (about three seconds
after the main motor begins rotation). The leading edge of the paper should have advanced past
the toner cartridge.
3 Remove the toner cartridge.
4 Open the toner cartridge drum shield to view the drum surface.
If a dark and distinct toner image is present on the drum’s surface, assume that the first four
functions of the electrophotographic process are functioning (cleaning, conditioning, writing, and
developing–see chapter 5), and troubleshoot the failure as a transfer or fusing problem.
If no image is present on the photosensitive drum, perform all the following functional checks.
Drum rotation functional check:
The photosensitive drum, located in the toner cartridge, must rotate for the print process to work. The
photosensitive drum receives its drive from the main drive assembly. To verify whether the drum is
rotating:
1 Open the top cover.
2 Remove the toner cartridge.
3 Mark the cartridge’s drive gear with a felt-tipped marker. Note the position of the mark.
4 Install the toner cartridge and close the top cover. The start-up sequence should rotate the drum
enough to move the marked gear.
5 Open the printer and inspect the marked gear. Verify that the mark moved. If the gear did not
move, inspect the main drive assembly to ensure that it is meshing with the toner cartridge
gears. If the drive gears function and the drum does not move, replace the toner cartridge.
Note: This test is especially important if refilled toner cartridges are in use.
